Dark alarm

There will be a certain proportion of suitcases whose contents are so optically thick that it is impossible to achieve sufficient penetration to acquire a useful number of photons in the diffraction profile. This renders evaluation impossible. Such an impenetrable suitcase raises a dark (sometimes called shield ) alarm. Clearly, the most effective way of reducing the dark alarm rate is to raise the mean photon energy. It is in this respect that the HETRA method of diffraction profile analysis (Section 2.3.1.) may prove helpful as it utilizes photons at the high-energy limit, where the suitcase is most transparent. 

Mean Z Organic explosives tend to be oxygen-rich leading to enhanced mean atomic numbers HETRA analysis of diffraction profile yields mean Z. Section 2.4.1.1. details significance for dark alarms... 

All of these signals create the greatest alarm in the viewer. The erect position and the control it implies are carefully cherished and protected. "Up" is associated with light and hope in our minds, "down" with darkness, pain, and punishment. The appearance of helplessness and loss of control we view as a demonstration of our vulnerability, as a reminder that our paths, which seem glorious, may suddenly be cut short. These threatening signals evoke in us intensive anticipatory activity. 

When the weather broke at last, Tompkins set the alarm clock an hour earlier and didn t tell anyone, hoping to get his stiff, grumbling friends up and out while the clear skies held. In bitterly cold darkness they began to climb at two-thirty in the morning, using a new, untried route, reaching the cloud-shrouded summit at seven that night. They... 

Travelling at great speed, the cloud — a mixture of chlorine and phosgene — outstripped the alarm system of gongs and klaxons and took hundreds of men unawares one man was gassed five miles behind the front line. Panic set in on the dark winter morning as shell fire cut all the telephone wires to the front. It was mid-afternoon... 

Although the M8 detector/alarm solved the advance warning problem, soldiers still needed a quick test to confirm the presence of chemical agents. The problem was solved with the standardization of M8 detector paper in 1973. The paper was a Canadian development. It was packaged in booklets of 25 sheets (perforated for easy removal) sized 4 x 2 x/2 in. M8 detector paper turned dark blue for V agents, yellow for G-series agents, and red for mustard agent.161... 

In the commandeered spaceport management office used to run the habitat s SD network, every single alarm tripped at once. The whole room was flooded with red light from AV projectors and holoscreens. Then the power went off, plunging the crew into darkness. 

Simple LCDs. The simplest LCD displays, such as calculators and watches, typically do not have their own light sources. Instead, they have what is known as passive display. In back of the LCD display is a reflective surface. Light enters the display and then bounces off the reflective surface to allow for the screen display. Simple LCDs are monochromatic and have specific areas (typically bars or dots) that become light or dark. While these devices are lower-powered, some do still use a light source of their own. Alarm clocks, for example, have light-emitting diodes (LEDs) as part of their display so that they can be seen in the dark. 

When control chart signals an out of control alarm (e.g., color inhomogeneity, unusual colors such as black or dark green), it is difficult for process owners to determine its root causes because the Hotelling 7 does not provide in-depth information. Therefore, we recommend using the contribution of color values L, a, b, h, C, Sl, Sa, Sb, Sb, and Sc and estimate maximum contribution of each sample in mean vector. 

Contradictory alarms led to the aircrew losing situation awareness. In the darkness, they had no other information except their instrumentation, and that instrumentation was not helpful. 

The two flight crew were now over the ocean and trying to fly the aircraft manually to return to Lima in darkness, all the time with abnormal or non-functioning altitude and airspeed indications, and with the Electronic Flight Information System generating lots of alarms. 

Figure 21.9 provides a general comparison of univariate and multivariate SPC techniques (Alt et al., 1998). When two variables, xi and X2, are monitored individually, the two sets of control limits define a rectangular region, as shown in Fig. 21.9. In analogy with Example 21.5, the multivariate control limits define the dark, ellipsoidal region that represents in-control behavior. Figure 21.9 demonstrates that the application of univariate SPC techniques to correlated multivariate data can result in two types of misclassification false alarms and out-of-control conditions that are not detected. The latter type of misclassification occurred at sample 8 for the two Shewhart charts in Fig. 21.8.

The resistance of an LDR in total darkness is about 10Mf2, in normal room lighting about 5 kQ, and in bright sunlight about 100 ff. They can carry tens of milliamperes, an amount which is sufficient to operate a relay. The LDR uses this characteristic to switch on automatically street lighting and security alarms. 

We use our sense of touch to evaluate the size and shape of physical objects. Often this is done in conjunction with our sense of sight, but also without. We can reach into our pocket and easily determine the difference between various coins, or we can reach for the bed stand in the dark and easily find the snooze button on the alarm clock. 

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